黄芩提取物中黄酮类成分血浆蛋白结合率的测定

目的建立同时测定黄芩总黄酮部位中4种黄酮类成分在大鼠血浆中药物浓度的方法,并测定其体外血浆蛋白结合率。方法平衡透析法测定黄芩黄酮类成分血浆蛋白结合率,以高丽槐素为内标,生物样本用甲醇沉淀蛋白进行预处理,采用HPLC法测定4种黄酮类成分在透析内、外液中的浓度。结果在低、中、高3种浓度下,黄芩苷(BL)和汉黄芩苷(WL)的血浆蛋白质结合率随给药浓度的增大而降低(BL:82.03%→77.25%→67.17%;WL:82.24%→76.08%→69.87%),而汉黄芩素(W)和千层纸素A(OA)则呈现非质量浓度依赖性,其平均血浆蛋白结合率分别为(89.66±1.19)%、(88.56±1.87)%。结论该文所建立的测定方法简便、灵敏、专属性强。4个黄酮类成分在大鼠体外均有较高的血浆蛋白结合率。

Determination of plasma protein binding rate of multicomponent in scutellaria baicalensis Georgi

Aim To establish a RP-HPLC method for determination of concentration of four major flavonoids,namely baicalin(BL),wogonoside(WL),wogonin(W) and oroxylin A(OA),in the total flavonoids extract of scutellaria baicalensis Georgi in rat plasma and to study the plasma protein binding rate.Methods The equilibrium dialysis was carried out to determine the plasma protein binding rate of the target compounds.The plasma samples were extracted by protein precipitation with methanol.With the use of maackiain as the internal standard,the concen-tration of the multicomponent inside and outside the dialysis membranes was determined by HPLC method.Results The plasma protein binding rates of baicalin and wogonoside decreased with increasing of concentration in a concentration-dependent manner(BL:82.03%→77.25%→67.17%;WL:82.24%→76.08%→69.87%),while were not the same of wogonin and oroxylin A.The average plasma protein bingding rates of wogonin and oroxylin A were(89.66±1.19)% and(88.56±1.87)%,respectively.Conclusions The HPLC method established in the paper is simple,sensitive,little interferential and stable.The four major compounds in the total flavonoids extract of scutellaria baicalensis Georgi have high capacity in binding plasma protein in rat in vitro.